<p><p><h2>Preferred Design Procedure</h2>No Federal Highway Administration (FHWA) guidance exists for the design of Sand Compaction Piles (SCPs). Design methods do exist based on the soil type to be improved. The methods presented are generally applicable to both support of embankments and structures. One generally accepted design method exists for the design of SCPs in clay soils. Four different methods (A through D) exist for the design of SCPs in sandy soils. Kitazume (2005) provides guidance for selecting an appropriate design procedure for SCPs in sandy soils based on the application. Methods are also available for designing SCPs to support embankments on clayey soils and for mitigation of liquefaction and lateral spreading.</p><p>The depth to which the casing is driven and extracted, SCP fill material, spacing or sand volume, and casing diameter must be determined during design. Kitazume (2005) and Murakami et al. (2006) provide guidance for selecting an appropriate backfill material. Construction, materials, and methods of analysis of SCPs are presented in subsequent sections. After the design summaries, Table 1 provides the typical inputs and outputs required for design and analysis.</p></p>
<p><p><h2>References</h2>Aboshi, H., Ichimoto, E., Enoki, M., and Harada, K. (1979). “The ‘Compozer’ – a method to improve characteristics of soft clays by inclusion of large diameter sand columns.” International Conference on Soil Reinforcement, (Reinforced Earth and other Techniques), Paris, pp. 211-216.</p><p>Aboshi, H., Mizuno, Y., and Kuwabara, M. (1991). “Present state of sand compaction pile in Japan.”<em> Deep Foundation Improvements: Design, Construction, and Testing</em><strong>. </strong><u>ASTM</u> <u>STP</u> <u>1089</u>, Melvin I. Esrig and Robert C. Bachus, Eds., American Society for Testing and Materials, Philadelphia, 1991.</p><p>Akiyoshi, T., Fuchida, K., Hyodo, T., and Fang, H.L. (1993). “Liquefaction analyses of sandy ground improvement by sand compaction piles.” Soil Dynamics and Earthquake Engineering, 12, 299-307.</p><p>Asaoka, A., Matsuo, M., and Kodaka, T. (1991). “Undrained Bearing Capacity of Clay with Sand Piles.” Proc. of the 9th ARC on SMFE Vol.1, 1991.</p><p>Asaoka, A., Matsuo, M., and Kodaka, T. (1994). “Bearing Capacity of Clay Improved with Sand Compaction Piles.” Proc. of the 13th ICSMFE Vol.2, 1994.</p><p>Barksdale, R.D. (1987). <em>State of the Art for Design and Construction of Sand Compaction Piles</em>. Technical Report REMR-GT-4, prepared for Department of the Army, US Army Corps of Engineers, November, 55p.</p><p>Barksdale, R. D. and Takefumi, T. (1991). “Design, construction, and testing of sand compaction piles.” Deep Foundation Improvements: Design, Construction, and Testing, ASTM STP 1089, 4-18.</p><p>Idriss, I.M. and Boulanger, R.W. (2008). <em>Soil Liquefaction During Earthquakes</em>, Earthquake Engineering Research Institute Monograph MNO-12, 235 pp.</p><p>Kitazume, M. (2005). <em>The Sand Compaction Pile Method</em>, Taylor & Francis, 2005, 232p.</p><p>Mizuno, Y., Shibata, W., and Kanda, Y. (1989). “Trail Embankment with Sand Compaction Pile Method at Muar Flats.” Proceedings of the International Symposium on Trial Embankments on Malaysian Marine Clays, 2, pp. 2-53-2-66.</p><p>Mizuno, K., Matsumoto, H., Tsuchida, T. (2006). “Finite element analysis of ground improved by Sand Compaction Pile method.” Geomechanics and Geotechnics of Particulate Media, 449-455.</p><p>Murakami, S., Higashi, S., Nakai, N., Seki, T., and Tsubio, H. (2006). “Characteristics of granular filling materials as sand compaction pile.” <em>Geomechanics and Geotechnics of Particulate Media</em>, 457-462.</p><p>Tanimoto, K. (1973). “Introduction to the Sand Compaction Pile Method as Applied to Stabilization of Soft Foundation Grounds.” <em>Division of Applied Geomechanics Report No. 6</em>, Commonwealth Scientific and Industrial Research Organization, Australia, pp. 1-14.</p><p>Youd, T.L., Idriss, I.M., Andrus, R.D., Arango. I., Castro, G., Christian, J.T., Dobry, R., Finn, W.D.L., Harder, L.F., Hynes, M.E., Ishihara, K., Koester, J.P., Liao, S.S.C., Marcuson, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K., Seed, R.B., and Stokoe, K.H. (2001). “Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils”, <em>J. of Geotechnical and Geoenvironmental Engineering</em>, ASCE, Vol. 127, No. 10, pp. 817 - 833.</p><p><a href="http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282001%29127…;
<div class='content-section' id='construction-considerations-in-design' title='Construction Considerations in Design'><p><p><div class="grayed-title"><strong>Construction Considerations in Design</strong></div><strong>Supporting Reference(s):<br></strong><em>Barksdale and Takefumi (1991)<br>Kitazume (2005)<br></em></p><p>The construction of a SCP involves driving a casing pipe into the ground to a prescribed depth, extracting the casing pipe to a designated amount (H<sub>E</sub>), feeding sand into the casing pipe, and compacting the sand by either re-driving the casing pipe a certain length (H<sub>D</sub>) or by a hammering probe in the middle of the casing pipe. Various methods of installing SCPs exist including:<br><ol> <li>Vibrating compaction technique<br><ol style="list-style-type: lower-alpha;"> <li>Vertical vibrating compaction technique</li> <li>Vertical and horizontal vibrating technique</li> <li>Vibro-compaction-device technique</li></ol></li> <li>Static compaction technique (non-vibratory)<br><ol style="list-style-type: lower-alpha;"> <li>Rotation and wave compaction technique</li> <li>Double casing pipes compaction technique</li> <li>Rotary compaction-device technique</li></ol></li> <li>Hammering compaction technique</li></ol>The most commonly applied technique is the vertical vibrating compaction technique. However, depending on the function of the SCP and backfill material, one method will be preferable to another. Kitazume (2005) compares the methods, offers guidance for method selection, and provides typical retrieval and penetration depths of the casing pipe. For construction purposes, the distance the casing must be re-driven (H<sub>D</sub>) to achieve the desired density is defined by a relationship among the distance it is extracted before re-driving (H<sub>E</sub>), the cross sectional area of the casing, and the cross sectional area of the SCP. The method to determine H<sub>E </sub>and H<sub>D</sub> can be found in Barksdale and Takefumi (1991).</p></p></div>
<div class='content-section' id='summary-of-sand-compaction-pile-material-considerations' title='Summary of Sand Compaction Pile Material Considerations'><p><p><div class="grayed-title"><strong>Summary of Sand Compaction Pile Material Considerations</strong></div><strong>Supporting Reference(s):<br></strong><em>Kitazume (2005)<br>Murakami et al. (2006)<br>Tanimoto (1973)</em></p><p>Tables 1 and 2 in Murakami et al. (2006) provide a scope of applications for materials substituted for sand in SCPs when sand is no longer economical. Other granular materials, such as stone, construction waste, slag, oyster shells, and granulated coal ashes have been used for pile material. Design considerations based on fill material and site conditions are discussed. Tanimoto (1973) suggests mixing cement, gravel, or lime into the SCP sand in order to increase the SCPs bearing capacity.</p><p>Fill material with low fines content and high strength is preferable to prevent particle crushing during installation. Ideally, the nonplastic fines content (F<sub>c</sub>) of the SCP should be no greater than 5%. However, for projects with high replacement ratios, it is acceptable to have a fines content up to 15%. For a fines content between 10 and 15%, the SCP should not be relied on for drainage of the in-situ soil. Kitazume (2005) provides recommended soil particle distribution suitable for the SCP method.</p></p></div>